Add setting up an Instance via the UI instead of GraphQL

[mszostok]

Description

Changes proposed in this pull request:

• Add setting up an Instance via the UI instead of GraphQL

Testing

It requires a local UI version from https://github.com/kubeshop/botkube-cloud/pull/1137

1. In my case, recreated local control-plane with mine own Slack instance.
2. Make sure you have a trial subscribed and a placeholder instance created.

3. Next, I exported following properties:

   export BOTKUBE_CLOUD_API_BASE_URL='http://localhost:8080'
   export BOTKUBE_CLOUD_UI_BASE_URL='http://localhost:3000'
   export BOTKUBE_CLOUD_EMAIL='your_user'
   export BOTKUBE_CLOUD_PASSWORD='your_pass'
   export BOTKUBE_CLOUD_TEAM_ORGANIZATION_ID='your_org_id'
   export DEBUG_MODE='true'
   
   export SLACK_WORKSPACE_NAME='your_workspace'
   export SLACK_EMAIL='your workspace email'
   export SLACK_PASSWORD='pass ' # by default pass is not set, see: https://slack.com/help/articles/201909068-Reset-your-password#h_01F256P7NEHPDZ7FT513SAZVBR
   
   export SLACK_TESTER_BOT_NAME='your tester app'
   export SLACK_TESTER_TESTER_BOT_TOKEN='tester slack app token'
   export SLACK_TESTER_CLOUD_TESTER_NAME='your cloud app'
   export BOTKUBE_CLI_BINARY_PATH="botkube" 

4. Finally, executed test with:

   cd tests
   go test -tags=cloud_slack_dev_e2e -v -timeout 30m  -count 1 ./cloud-slack-dev-e2e/...

Related issue(s)

Fix https://github.com/kubeshop/botkube-cloud/issues/886

[mszostok]

I executed the workflow 3 times in a row, all passed: https://github.com/kubeshop/botkube/actions/runs/9572807087?pr=1458

[mszostok]

I had to skip the plugin update flow because it was too flaky.

1. The screenshot shows that the button is there and enabled.

2. However, the assertion can't pass, with logs like:

   === NAME  TestCloudSlackE2E/Creating_Botkube_Instance_with_newly_added_Slack_Workspace
       botkube_page_helpers_test.go:215: Submitting changes
   [rod] 2024/06/18 20:33:12 [wait] stable <page:AE0EEF2A>
   [rod] 2024/06/18 20:33:12 [query] rod.elementR("button","/Deploy changes/i")  <page:AE0EEF2A>
   [rod] 2024/06/18 20:33:12 [wait] interactable <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:12 [input] scroll into view <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:12 [wait] visible <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:12 [wait] stable RAF <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:12 [input] scroll into view <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:12 [wait] visible <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:12 [wait] stable RAF <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:13 [input] scroll into view <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:13 [wait] visible <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:13 [wait] stable RAF <button.ant-btn.css-153za3i.ant-btn-primary>
   [rod] 2024/06/18 20:33:14 [input] scroll into view <button.ant-btn.css-153za3i.ant-btn-primary>

Notes:

• They are deterministic locally. During development, I got a 100% pass rate.
• In headless mode, it becomes flaky in CI.
• I think that the go-rod engine itself is not very reliable, and it doesn't work well with our UI.
• Maybe the Playwright assertion engine is more stable. It’s something worth testing when we revisit it.